The use of multiple blade saw systems is widespread in the lumber industry. Certain types of multiple blade saw systems use very thin circular saw blades. Such thin saw blades, however, require saw guide systems to prevent warping and deformation of the blade during use. Many existing guiding systems use large babbitt saw guides which typically require large amounts of cooling water to cool both the saw blades and saw guides while the saws are cutting.
An alternative approach for preventing excess accumulation of heat in multiple saw assemblies, with little or no water, is described in U.S. Pat. No. 4,635,513 (incorporated herein by reference). This system employs a plurality of individual saw guide blocks, each of which include separate channels to run oil mist and water mist to the saw blade. It was found that by applying very small amounts of lubricating oil through the saw guides onto the saw blade, the need to apply water to the blades for cooling is greatly reduced or eliminated altogether. The use of such systems has been widely adopted.
The system described in U.S. Pat. No. 4.635,513 does, however, suffer from one particular problem in that the small orifices in the saw guide tend to plug with very fine saw dust which stops the flow of lubricant and coolant to the saw blade. Such plugging can cause the saw to overheat resulting in damage to both the saw guide and the saw itself. Additionally, even partial plugging can cause pressure imbalances on opposite sides of the guide, which imbalances can cause increased saw friction and in the worst case, misalignment of the adjacent blade.
A further problem with saw guide systems in general is that the guide blocks require frequent changing, typically after only about 40 hours. The introduction of oil onto the saw guides, as disclosed in the 4,635,513 patent, has significantly increased their life, typically to 100 hours or longer; however, the guides must still be changed once a week or more frequently.
For the above reasons, it would be desirable to provide a saw guide block which is capable of applying oil without the plugging associated with the prior blocks discussed above. It would be particularly desirable if such guide blocks were also to enjoy extended useful lives in order to reduce costs associated with frequent changes.